Ultra high frequency tube



April 15, 1941. l. E. MOUROMTSEFF EIAL ,2 8,596

ULTRA HIGH FREQUENCY TUBE Filed NOV. 30, 1938 g MM ATTO R N EY PatentedApr. 15, 1941 2,238,59 6 ULTRA HIGH FREQUENCY TUBE Ilia E. Mouromtself,Montclair, and George M.

Dinnick, Bloomfield, N. 1., asaignors to Westinghouse Electric &Manufacturing Company, East Pittsburgh, Pa., a corporation ofPennsylvania Application November 30, 1938, Serial No. 243,116

ficlaims.

The invention relates to electron discharge devices and particularlysuch devices that are suitable for ultra high frequency.

An object of the invention is to provide a discharge tube for ultra highfrequency having an output of 100 watts and even up to 250 or 300 wattsoutput.

Another object of the invention is to provide a discharge device havinga minimum of inductance between the leads to the electrodes.

Other objects and advantages of the invention will be apparent from thefollowing description and drawing, in which:

Fig. 1 is a view, partly in cross-section and partly in elevation. .of atube embodying the invention.

Fig. 2 is an enlarged view on lines 1I1I of Fig. 1.

Fig. 3 is an enlarged view on lines IIIIII of Fi 1.

Fig. 4 is an enlarged view of the filament and connecting supportingstructure illustratled in Fig. 1.

Fig. 5 is a top view of a modification of the filament structure.

Fig. 6 is a front elevation of the top portion of the filament structureof Fig. 5.

The invention in particular relates to electron discharge devicessuitable for high frequencies of 60 to 260 or 300 megacycles and havinga wave length of approximately one to five meters. Tubes utilized inhigh frequency work have heretofore been limited to a very small poweroutput. The dimculty has been to emciently dissipate the heat generatedin the grid. Prior schemes for cooling the grid of large size tubes areobviously inapplicable to the ultra. high frequency tube where theelectrodes must be closely spaced together for high frequency use. Oneof the specific objects of our invention is to provide means foreffectively dissipating heat from the grid structure to the casing ofthe discharge device without interfering in any way with the spacingbetween the grid and the other electrodes.

Another dimculty in the design of these tubes has been the inductancebetween the leads to the electrodes. The design of our leads provides aminimum of inductance between the leads of the device.

In the drawing, we have illustrated a preferred embodiment such asillustrated in Fig. 1. The figure is drawn to approximately a 50%greater size than the actual tube constructed according to ourinvention. An exterior anode III is utilized in a hollow tubular formhaving a flare ll making a feather edge seal l2 with the glassinsulating portion l3 of the casing. The diameter of the active portionf the anode is very small for tubes of this wattage capacity and may beof an interior diameter of a half to three-quarters of an inch as anexample. It will be noted that the insulating part of the casing I3 isenlarged to several times this diameter to provide a wide spacing forthe other electrode leads therethrough.

At the opposite end of the tube is a metal portion [4 having a featherseal I5 with the insulatingportion. This metal portion I4 is preferablyof a cup or knobb'ed shape having a flare l6 terminating in the featherseal. Fitting into this cup or knobbed shape 14 is a knob of copper l'lhaving a very tight engagement with the copper portion H. The knob l1and the enclosing casing ll are of sumcient length to provide adequateair cooling and dissipation of heat therefrom. Any suitable shape finsmay, of course, be made integral with 'or to fit upon the knob of thecasing l4. Integrally attached to the knob I1 is a shaft-l8 extendingtowards the upper part of the tube. This shaft of copper is of such asize and thickness that there is substantially temperature equilibriumbetween the tip of the knob I1 and the inner terminal IQ of the shaftl8. In case the inner tip I! is at 100, or 200 degrees, the knob ll willnot be more than 10 degrees different therefrom. Around the inner end IQof this copper shaft is a ring or collar 20 securingthe ends 2| of thegrid wires thereto. This support for the grid wires may take anywellknown mechanical form such as the ring 20 sweated on to the end ofthe copper portion with holes providing the very tight frictional fitdrilled into the ring 20. The top of the copper shaft may have a hole 22drilled therein to help the compression of the ring 20 thereon. The topof the copper shaft may also be split about the hole 20 and have theends of the grid wires 2| in contact thereto and the ring 20 be in theform of a clamp compressing the ends 2| to the top of the copper shaft.As illustrated in the drawing, the grid wires are spaced about the topof the copper shaft to provide for an assembling of the cathodeconnection to be hereafter described and then these grid wires are bentinwardly at 23 and then extend parallel and longitudinal at 24 with thedesired spacing from the anode III which encloses them. The grid wires,as illustrated, comprise eight, although a greater or less number can beused. An inverted cap 25 is preferably welded to the top of these gridwires to maintain them in place.

Inside of the grid are the filament wires 26 preferably 01' thoriatedtungsten extending parallel and concentric with the grid wires and theanode, This filament construction is more clearly disclosed in theenlarged detailed view in Fig. 4. The top of the grid wires are bentover at 21 and have another smaller wire 28 binding their ends 29together, The wire 28 and the ends 29 may be welded or solderedtogether. The number of filament wires illustrated is six although ofcourse this number may be varied. It is desirable, however, to have thenumber an even one. An insulator 30 preferably of a ceramic materialsupports two discs 3| and 32. The top disc 3| rests on the insulator andis fastened thereto by a. bolt 33 extending through the insulator 30.Every other filament 26 terminates adjacent the periphery of this disc3| preferably by having a wire 34 wound around the end of the filamentand welded or soldered to the disc where the filament 26 passestherethrough, The disc 32 is placed on a lower reduced portion of theinsulator 30 which arrangement maintains it in spaced relationship fromthe disc 3| on top of the insulator. disc 3| has a cut out portion 35located at the portions of the periphery intermediate the places ofconnection of the ends of the filament 26 that are connected thereto.This cut out portion 35, is sufficiently large so that the alternatingfilaments may extend down to the disc 32 to be secured thereto in amanner corresponding to the attachment of the other filaments to thedisc 3|, The upper disc 3| accordingly has the shape of a circle withparts regularly removed about its perforate. Other shapes, however, maybe used to provide a clearance for the alternating filaments to reachthe lower disc 32. The bolt 33 preferably passes through anotherinsulator 35 and a fiat arm 31 makes contact with the bolt 33 at thelower surface of the insulator 36. Another arm 38 encloses a reduceddiameter of the insulator 36 and a hollow sleeve 39 connects this flatarm 38 and the disc 32.

The bolt heads 33 acting on the upper disc 3| and the lower contact arm31 bind the structure together. The fiat arms 31 and 38 pass through thespace between two of the grid wires and at a suitable distance therefromare connected at right angles to two solid rod standards 40 and 4| thatare sealed through the insulated casing by the broad and extended seal42 as illustrated. The conducting rods 40 and 4| are in turn connectedto flexible conductors 43 by means of a sleeve 44 and in a manner moreparticularly described in Patent #1,834,132 of W. L. Miller, issuedDecember 1, 1931, for Leading-in conductor.

A shield 45 is preferably placed about the grid wires on a line with thefeather edge seal l2 be tween the anode and the insulating portion ofthe casing in order that this seal may not be under any electrostaticstress. This shield will also help in maintaining the shape andalignment of the lower portion of the grid wires.

In Figs. 5 and 6 is disclosed a modification of the filament structureof Fig. 4. A thoriated filament 4"! is secured to the upper disc 3| andextends upward where it touches the upper portion of two other wires 46and 48 and is bound thereto by a wire 49 around the very top portion ofthese three wires. The other end of each of these wires, 46, 41, and 48,then bends downward through the cut out portions 35 of the disc 3| tomake contact with the disc 32.

The cathode heating current enters the tube, for example, through thestandard 40, passes at The upper right angles to the fiat arm 31 to thebolt 33 and from this bolt, by means of the disc 3|, to the one, two,three or more wires connected thereto, through the thoriated filamentwires and back to the other disc 32 through the hollow cylinder sleeve39 to the fiat arm connection 38 and then to the standard 4| leadingoutside the tube.

In operation, the grid will provide an output way beyond the output ofthe tubes used for the high frequency, This, as previously mentioned, isdue to the efficient cooling of the grid. The high temperature of thegrid wires will be applied to the upper edge I9 of the copper shaft I8and due to the thickness of the copper shaft, the knob I! will beapproximately of the same temperature. In other words, the shaft It!acts as a temperature equalizer between the end of the grid and themiddle portion l4 of the casing acting as a grid lead-in. The shaft l8provides a broad and capable path for the transference of heat from thegrid to the exterior of the casing. By reason of this construction, anoutput of 100, 150, 250 or 300 watts can be realized. Because of thefact that the grid cooling means does not interrupt the spacing of thegrid with the filament and anode, a frequency of to 260 or 300megacycles can be utilized with the construction disclosed.

Many modifications can be made in the form, number and arrangement ofthe various elements and their combinations in the preferred embodimentsillustrated. As an example, the grid struc-- ture of Fig. 1 could takethe form of the wires bound at the top in Fig. 4.

We claim:

1. A discharge device comprising a container having an exterior anode,grid and cathode, said grid being located within the interior portion ofsaid container and a connection making a contact to said grid within theinterior portion of the container and making a contact with said casinand substantially equalizing the temperature within ten degrees at thecontact to the casing to the temperature at the contact to said grid,and means to remove heat from both said exterior anode and from thecontact of said grid connection with said casing.

2. A discharge device comprising a container having an anode, cathodeand grid, said grid being located within the interior portion of saidcontainer, a conductive portion of the casing and a connection makincontact to the grid within the interior portion of the container and tothe said conductive portion of the casing substantially equalizing thetemperature between said two contacts within ten degrees.

3. A discharge device comprising a container having an anode, grid andcathode, said grid being located within the interior portion of saidcontainer, a cup-shaped conductive portion having its rim sealed in thewall of said container, and a thick connection approximately thediameter of the grid extending from the grid to the interior surface ofsaid cup-shaped portion.

4. An electrode structure comprising a thick rod of high heatconductivity, an opening in one end, said rod having a reduced diameteraround said opening, a plurality of wires forming a cage and meansfastening said wires about the reduced diameter around said opening.

5. A discharge device comprising a container having an anode, grid andcathode, said grid being located within the interior portion of saidcontainer, a rod of high heat conductivity extending from said grid tothe container wall, said rod having a diameter approximately the largestdiameter of said grid, said container having a 7 metal cup-shapedportion, and said rod seated in said cup-shaped portion.

6. A discharge device comprising a container having an anode, grid andcathode, said grid being located within the interior portion of saidcontainer, a rod 01 high heat conductivity extending from said grid tothe container wail, said rod having a diameter approximately the largestdiameter of said grid, said container having a metal cup-shaped portionbulged outwardly of said container, and said rod seated in saidcupshaped portion.

ILIA E. MOUROMTSEFF.

GEORGE M. DINNICK.

